PURPOSE: Thirty-four pediatric age patients with unilateral moyamoya disease (MMD) were reviewed to analyze the natural history and the predictive factors for progression to bilateral MMD.
METHODS: Forty out of 259 MMD patients cared for between January 2000 and June 2008 in the Severance Hospital had unilateral lesion. These patients were followed for a mean of 32.3 months for their symptoms and imaging studies. Thirty-four out of 40 patients were included in this study. Magnetic resonance angiography (MRA) and magnetic resonance perfusion (MR perfusion) images were taken for all patients for initial diagnosis and repeated at 6 months from the initial diagnosis and then at yearly basis. Clinical manifestations, the results of imaging studies, outcome of the indirect revascularization procedure, and the progression of the lesion were reviewed in this study.
RESULTS: Of these 34 patients, contralateral progression was identified in 20 patients (58.8%). Fourteen (70%) out of the 20 patients presented with anterior cerebral artery abnormalities at diagnosis progressed to bilateral disease as well as did 5 (83%) out of 6 patients with middle cerebral artery lesions at the initial examination. Among the 34 patients, six exhibited familial history of MMD and all of them progressed to bilateral disease (100%, p < 0.005).
CONCLUSION: Careful and long-term follow-up would be essential to evaluate the hemodynamic status and progression to bilateral disease in unilateral MMD patients to make prompt decision for a surgical revascularization.